Aircraft with gas turbine engine having outer bypass elements removed

Abstract

A small aircraft such as a UAV having a gas turbine engine with the outer bypass elements removed from the engine, and where the airframe is modified to form the bypass duct and exhaust nozzle for the fan produced bypass flow of the engine in order to reduce weight, size and cost of the small aircraft. The outer casing and the exhaust nozzle is removed from the engine and optimally integrated into the airframe structure.

I claim the following: 
     
       1. A small aircraft comprising:
 an airframe; 
 a small gas turbine engine with a fan to produce a bypass flow; 
 an outer casing of the small gas turbine engine being removed; and, 
 an inner wall of the airframe forming a bypass duct for the bypass flow of the fan. 
 
     
     
       2. The small aircraft of  claim 1 , and further comprising:
 the small aircraft is an unmanned aero vehicle. 
 
     
     
       3. The small aircraft of  claim 1 , and further comprising:
 an exhaust nozzle is removed from the small gas turbine engine; and, 
 a new exhaust nozzle is secured to the airframe. 
 
     
     
       4. The small aircraft of  claim 1 , and further comprising:
 the outer casing of the small gas turbine engine is removed from a location aft of the fan and a compressor of the engine and includes removal of an exhaust nozzle. 
 
     
     
       5. The small aircraft of  claim 1 , and further comprising:
 the airframe forming the bypass duct is rectangular in cross-sectional shape. 
 
     
     
       6. The small aircraft of  claim 1 , and further comprising:
 the airframe forming the bypass duct is trapezoidal in cross-sectional shape. 
 
     
     
       7. The small aircraft of  claim 3 , and further comprising:
 the exhaust is unmixed and the nozzle is non-axisymmetric and is placed such that the cold bypass stream shields the hot core stream to reduce the IR signature. 
 
     
     
       8. The small aircraft of  claim 7 , and further comprising:
 the bypass duct transitions from annular aft of the fan to a discrete duct or ducts prior to entering the non-axisymmetric nozzle.